Each TeraBeam system comprises two distributed feedback (DFB) lasers with built-in optical isolators and fiber-optic beam combination. Available at 780 nm and 1.5 µm, the TeraBeam matches the excitation wavelengths of GaAs and InGaAs terahertz emitters, respectively. TOPTICA carefully selects the laser diodes with respect to their thermal tuning range. The DLC Smart controls the temperatures of both lasers with unmatched precision.